content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * ---------------------
   * SimpleTimePeriod.java
   * ---------------------
   * (C) Copyright 2002-2008, by Object Refinery Limited and Contributors.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 07-Oct-2002 : Added Javadocs (DG);
   * 10-Jan-2003 : Renamed TimeAllocation --> SimpleTimePeriod (DG);
   * 13-Mar-2003 : Added equals() method, and Serializable interface (DG);
   * 21-Oct-2003 : Added hashCode() method (DG);
   * 27-Jan-2005 : Implemented Comparable, to enable this class to be used
   *               in the TimeTableXYDataset class (DG);
   * 02-Jun-2008 : Fixed problem with fields being mutable (DG);
   *
   */
  
  package org.jfree.data.time;
  
  import java.io.Serializable;
  import java.util.Date;
  
  /**
   * An arbitrary period of time, measured to millisecond precision using
   * <code>java.util.Date</code>.
   * <p>
   * This class is intentionally immutable (that is, once constructed, you cannot
   * alter the start and end attributes).
   */
  public class SimpleTimePeriod implements TimePeriod, Comparable<TimePeriod>, Serializable {
  
      /** For serialization. */
      private static final long serialVersionUID = 8684672361131829554L;
  
      /** The start date/time. */
      private long start;
  
      /** The end date/time. */
      private long end;
  
      /**
       * Creates a new time allocation.
       *
       * @param start  the start date/time in milliseconds.
       * @param end  the end date/time in milliseconds.
       */
      public SimpleTimePeriod(long start, long end) {
          if (start > end) {
              throw new IllegalArgumentException("Requires start <= end.");
          }
          this.start = start;
          this.end = end;
      }
  
      /**
       * Creates a new time allocation.
       *
       * @param start  the start date/time (<code>null</code> not permitted).
       * @param end  the end date/time (<code>null</code> not permitted).
       */
      public SimpleTimePeriod(Date start, Date end) {
          this(start.getTime(), end.getTime());
      }
  
      /**
       * Returns the start date/time.
       *
       * @return The start date/time (never <code>null</code>).
       */
      @Override
      public Date getStart() {
          return new Date(this.start);
      }
  
      /**
       * Returns the start date/time in milliseconds.
       *
       * @return The start.
       *
       * @since 1.0.10.
       */
      public long getStartMillis() {
          return this.start;
      }
  
      /**
       * Returns the end date/time.
       *
       * @return The end date/time (never <code>null</code>).
       */
      @Override
      public Date getEnd() {
          return new Date(this.end);
      }
  
      /**
       * Returns the end date/time in milliseconds.
       *
       * @return The end.
       *
       * @since 1.0.10.
       */
      public long getEndMillis() {
          return this.end;
      }
  
      /**
       * Tests this time period instance for equality with an arbitrary object.
       * The object is considered equal if it is an instance of {@link TimePeriod}
       * and it has the same start and end dates.
       *
       * @param obj  the other object (<code>null</code> permitted).
       *
       * @return A boolean.
       */
      @Override
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (!(obj instanceof TimePeriod)) {
              return false;
          }
          TimePeriod that = (TimePeriod) obj;
          if (!this.getStart().equals(that.getStart())) {
              return false;
          }
          if (!this.getEnd().equals(that.getEnd())) {
              return false;
          }
          return true;
      }
  
      /**
       * Returns an integer that indicates the relative ordering of two
       * time periods.
       *
       * @param that  the object (<code>null</code> not permitted).
       *
       * @return An integer.
       *
       * @throws ClassCastException if <code>obj</code> is not an instance of
       *                            {@link TimePeriod}.
       */
      @Override
      public int compareTo(TimePeriod that) {
          long t0 = getStart().getTime();
          long t1 = getEnd().getTime();
          long m0 = t0 + (t1 - t0) / 2L;
          long t2 = that.getStart().getTime();
          long t3 = that.getEnd().getTime();
          long m1 = t2 + (t3 - t2) / 2L;
          if (m0 < m1) {
              return -1;
          }
          else if (m0 > m1) {
              return 1;
          }
          else {
              if (t0 < t2) {
                  return -1;
              }
              else if (t0 > t2) {
                  return 1;
              }
              else {
                  if (t1 < t3) {
                      return -1;
                  }
                  else if (t1 > t3) {
                      return 1;
                  }
                  else {
                      return 0;
                  }
              }
          }
      }
  
      /**
       * Returns a hash code for this object instance.  The approach described by
       * Joshua Bloch in "Effective Java" has been used here - see:
       * <p>
       * <code>http://developer.java.sun.com/
       * developer/Books/effectivejava/Chapter3.pdf</code>
       *
       * @return A hash code.
       */
      @Override
      public int hashCode() {
          int result = 17;
          result = 37 * result + (int) this.start;
          result = 37 * result + (int) this.end;
          return result;
      }
  
  }
  